Update on the situation of Pseudomonas syringae pv. actinidiae in Switzerland
In June 2011, the presence of Pseudomonas syringae pv. actinidiae (EPPO A2 List) was recorded for the first time (EPPO RS 2011/1968) in Switzerland. The bacterium was detected in a small commercial kiwifruit orchard in Meynier (canton of Geneva) where eradication measures were implemented. Since 2013, all commercial kiwifuit crops in all cantons of Switzerland have been placed under surveillance. The NPPO of Switzerland recently informed the EPPO Secretariat of the current situation of the disease on its territory.
- Eradication from the canton of Geneva
Although P. syringae pv. actinidiae was not a regulated pest in 2011 when it was first found in Meynier, eradication measures were immediately taken after this first finding. All plants in the plot were uprooted and destroyed. Subsequently a monitoring programme was established. Since 2011 all commercial kiwifruit crops (Actinidia spp.) in the canton of Geneva have been visually inspected. According to the monitoring data available for the canton of Geneva, no further findings of P. syringae pv. actinidiae have been made since 2011. Therefore, the Swiss NPPO considers that P. syringae pv. actinidiae has been successfully eradicated from the canton of Geneva.
- First findings in the cantons of Vaud and Thurgau
In June 2015, two plots of a commercial crop in Etoy (canton of Vaud) were found to be infested with P. syringae pv. actinidiae. The infestation on plot "A" (2.8 ha) was severe (95% of the plants showed symptoms). On the neighbouring plot "B" (0.6 ha) only a single plant was found to be positive. Planting on plot "A" started in 2013 with a lot of 1630 plants imported from an EU Member State. A few plants from the same lot were used for the replacement of individual plants in plot "B". In 2014 planting of plot "A" was supplemented with 450 additional plants that were imported from the same Member State (as in 2013) and with 1007 potted plants provided by a Swiss nursery (canton of Thurgau). The plants provided by the Swiss nursery had been imported from another EU Member State shortly before. Part of this lot remained in the Swiss nursery. In the framework of tracing-back studies carried out in 2015, the remaining plants of this lot were tested and found to be positive for P. syringae pv. actinidiae. As P. syringae pv. actinidiae is now a regulated pest in Switzerland, official phytosanitary measures were taken according to the Swiss regulations in force. The entire crop of plot "A" (2.8 ha) was uprooted and plants were burned. The single infested plant on plot "B" and all plants within a radius of 5 m were uprooted and burned. An intensive survey within a radius of 10 km around the infested plot is currently being carried out. All remaining plants from the imported lot delivered through the Swiss nursery were also destroyed.
The official pest status of Pseudomonas syringae pv. actinidiae in Switzerland is officially declared as: Transient: actionable, under eradication.
Sources
NPPO of Switzerland (2015-07).